Method and device for determining the visual acuity of a user

ABSTRACT

A method for determining the visual acuity, wherein two spaced outer markings and an orientation marking lying between but not on a straight connecting line are displayed to the user on a display in an individual test as part of a plurality of tests. The user is to move the orientation marking on the display perpendicularly to the straight connecting line by actuating the device until the user perceives the marking as lying on the straight connecting line. Afterwards, the electronic device registers the effective distance between the orientation marking and the connecting line. At least two tests are carried out in which the outer markings are arranged along the same main axis, and at least the vertical main axis and the horizontal main axis are measured. After the manipulation, the effective distance from the individual tests of the series is used for ascertaining the visual acuity.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Continuation of application Ser. No. 15/570,566 filed Oct. 30,2017, claiming priority based on International Application No.PCT/EP2016/058911 filed Apr. 21, 2016, claiming priority based onEuropean Patent Application No. 15 166 029.7, filed Apr. 30, 2015, thecontents of all of which are incorporated by reference herein in theirentirety.

TECHNICAL AREA

The present invention relates to a method and a device for determiningthe visual acuity of a user. In particular, it relates to a method whichenables the user, independently and regularly without great effort, overa relatively long time and, for example, in the scope of a medicaltreatment, to check these functions, in order then to be able to seekmedical aid in a timely manner if this is necessary.

PRIOR ART

Diverse methods are known from the prior art for checking or monitoringthe visual acuity, respectively. Thus, for example, U.S. Pat. No.4,798,456 describes a method, using which metamorphopsia can be measuredquantitatively, by presenting different images to the affected person,and the person subsequently being questioned about the perception.

For example, a handheld eyesight tester and a method for self-testing ofthe sight of a user using such a device are known from WO2010132304. Themethod ensures that deviations from the permissible spacing arecompensated for in a display of the handheld eyesight tester within anacceptable distance from the eye of the user. Various shapes aredisplayed on the display to the user, either dynamically or statically,in the scope of the method. The method also enables the input ofreactions of the user to the various shapes, which are in turndisplayed. Results of the self-test are determined from the reactionsgenerated by the user. In this case, for example, circles are displayedadjacent to deformed circles, and the user has to identify the deformedcircles.

A method for measuring the visual capacity of a user is known from U.S.Pat. No. 4,798,456, in which method two points, which are spaced apartbut fixed in the position thereof, are specified and the patient isrequested to displace a third point along the connecting axis of the twoouter fixed points into the center between these two fixed points.

A method is known from US 2005/122477, in which method a test pattern isspecified, and the user is requested to perform certain changes on thistest pattern, and conclusions are drawn about the vision behavior of theuser from the corresponding behavior feedback of the user. A similarmethod is known from US 2012/050685.

DESCRIPTION OF THE INVENTION

It is accordingly the object of the present invention to provide animproved method for determining the visual acuity (wherein this term isalso to include the field of vision) of a user, which can be carried outin a reliable and error-free manner without medical assistance.

This object is achieved by a method as claimed in claim 1 or a dataprocessing program for carrying out such a method, respectively, or by amobile electronic device having such a method.

The proposed test is used to measure the capacity of the visual system.However, an inference can also be drawn indirectly, via the capacity ofthe visual system, about general capacities of the user, for example theresponse capacity, the strength, or the state of relaxation.Accordingly, a conclusion can also be drawn indirectly about the generalphysiological state, for example also the degree of alcoholization or ingeneral the state under the influence of drugs or medications, under theinfluence of an illness which is possibly also not directly related tothe eyes and the visual capacity, or a mental state, or a combination ofthese aspects. The method checks the capacity for registering points inthe spatial relationship thereof in relation to one another. Thisquality of vision is known as so-called Vernier acuity. This visualcapacity is based on the visual performance of the retina andhigher-level structures in the visual signal processing. The accuracy ofthis visual performance can be influenced by various aging processes orpathological processes. These processes include age-related maculardegeneration (AMD), diabetic retinopathy, vascular occlusions of anytype in the retina and the optic tract, macular edema of any genesis(for example, postoperative, diabetic, inflammatory), diseases of theretina which result in displacement of the photoreceptors, for exampleepiretinal fibroplasia, vitreofoveal traction syndrome, and macularhole, as well as diseases of the optic nerve, for example glaucoma.

The location of the presented spots can be selected so that they arespecifically placed on the affected points of the retina. The selectionof the location of the points can be made on the basis of morphologicalexaminations, for example optical coherence tomography (OCT) or on thebasis of the results of prior examinations using the method describedhere (adaptive or learning method). In addition, upon repeatedapplication, by way of the comparative analysis of the precision and thespeed of the inputs and responses by the test person, the influence ofdaily performance variations or pathological changes of the brain on thetype or speed of image perception or the influence of exogenoussubstances such as alcohol or other sedative and hallucinogenicsubstances on the response capacity of the brain can be measured. By wayof the dynamic component of the Vernier acuity test, retina related andnon-retina related changes or variations of the measurement results canbe registered and the detection sensitivity of the system to functionalchanges of the retina can be increased.

Specifically, the present invention relates to a method for determiningthe visual acuity, in which the user completes a test series of multipleindividual test procedures carried out in succession. In this case, inthe scope of each individual test procedure, two spaced-apart outermarks, which are fixed within an individual test procedure, and analignment mark located therebetween but not on a connecting straightline of the outer marks are displayed on a display screen of anelectronic device. The user is now prompted, by actuating the electronicdevice, to displace the alignment mark on the display screenperpendicularly to the connecting straight line of the outer marks untilin the perception of the user the alignment mark lies on the connectingstraight line between the outer marks. In this manner, the user focuseshis vision on the alignment mark, but has to position it relative to theouter marks.

Subsequently, after completed displacement of the alignment mark by theuser, the electronic device registers and analyzes at least one of thefollowing registered parameters:

the effective spacing of the alignment mark from the connecting straightline after displacement of the alignment mark by the user;

the time which the user has required for the displacement of thealignment mark;

the number of direction changes during the displacement of the alignmentmark by the user.

The individual test procedure is typically ended by the user making acorresponding input, for example by the user acting on a field“continue” on the display screen.

In this case, typically at least two or at least three individual testprocedures are carried out, in which the outer marks are arranged alongthe same main axis or previously determined auxiliary axes, and whereinat least two different main axes are measured in the scope of one testseries. Subsequently, at least one of the registered parameters or, uponmeasurement of multiple parameters, preferably a combination of theregistered parameters is used as a measure for determining the visualacuity from the individual test procedures of the test series.

Conventional measuring methods for determining the Vernier acuity, forexample the Amsler grid, have the disadvantage that the tested personhas to focus on a certain point, but is requested to assess visualimpressions which are located outside the point focused on. In themethod described here, the situation is more or less reversed, withoutthe user noticing this, which substantially simplifies the reliabilityand the simplicity of the measurement.

The following definitions apply in conjunction with the presentinvention:

Electronic Device:

This is to be understood in general as a device which is capable ofproviding an image to a user. These are devices for monocular orbinocular display of two-dimensional or three-dimensional images. Theseaccordingly include mobile devices (for example tablets and smartphones)and personal computers (for example desktop computers and laptops), butalso projectors, head-mounted devices, interactive spectacles, 3Ddisplay devices, holographic display devices, (large-scale) screens,data spectacles, data helmets, hologram lasers, etc.

Display Screen:

This is to be understood not only as a display screen in the classicalmeaning, but rather in general a device for displaying two-dimensionalor three-dimensional images for one or both eyes. In other words, theterm includes not only conventional display screens, but rather alsodisplays projected on a surface, and also the display means as are used,for example, in data spectacles or in holographic displays. Displayscreens which are touch-sensitive are preferred.

Outer Marks:

The marks arranged outside the immediate visual area of attention of theuser are referred to as outer marks, wherein the shape thereof is notspecified further in principle, as long as they are capable of making animaginary connecting straight line therebetween visually conceivable tothe user. The outer marks, which can be formed, for example, as spots orstrokes or also circles or triangles, can be supplemented or amplifiedby additional aids, for example circles or shading, etc.

Alignment Mark:

The display element between the outer marks is referred to as thealignment mark. This element of the alignment mark is also not specifiedfurther in principle with respect to shape, as long as it enables thisouter mark to be positioned in the most comprehensible manner on theimaginary connecting straight line between the outer marks. Alignmentmark and outer marks can be displayed more or less positively on a lightbackground, but they also can be displayed more or less negatively on adark background. A mixed display is also conceivable, i.e., the outermarks are displayed as darker marks on a medium background and thealignment mark as lighter markings, or vice versa.

Spacing:

The spacing of the alignment mark is to be understood as the spacing ofthe alignment mark from the imaginary connecting straight line betweenthe two outer marks. The spacing is correspondingly equal to zero if thealignment mark is located precisely on the imaginary connecting straightline between the two outer marks. The spacing generally changes in thescope of an individual test procedure. Initially, an alignment markwhich is not located on a connecting straight line of the outer marks isdisplayed between the outer marks, i.e., the spacing is not equal tozero initially, the dimension of the initial spacing is preferablyspecified randomly, wherein for this initial value typically an absoluteminimum value and an absolute maximum value are set for this randomspecification. In the course of the individual test procedure, the userdisplaces the alignment mark along a direction perpendicular to theimaginary connecting straight line of the outer marks, he cannotdisplace the alignment mark at all along other axes, and at the end ofthe individual test procedure, a spacing results, which corresponds tothe effective spacing of the alignment mark from the connecting straightline after displacement of the alignment mark.

Offset:

The offset of the alignment mark is the position of the alignment markrelative to the distance between the two outer marks. If one considersthe imaginary connecting straight line between the two outer marks asthe x axis and the axis perpendicular thereto as the y axis, the offsetis thus accordingly the x coordinate of the alignment mark and theabove-defined spacing of the alignment mark is they coordinate of thealignment mark.

The relationships are graphically shown in FIG. 1b for the situation ofa horizontal main axis. The above-defined spacing corresponds to thedimension c in this figure, the distance between the outer marks 3 and 4corresponds to d, and the dimension a corresponds to the offset. Thealignment mark 5 can only be displaced along the displacement direction16, which extends perpendicularly to the connecting straight line 6.

Main Axes:

The main axes are understood as the vertical axis (vertical main axis)and the horizontal axis (horizontal main axis), as they appear to theuser upon the intended use of the display screen of the correspondingelectronic device. The direction of the corresponding main axiscorresponds to the imaginary connecting straight line between the twoouter marks.

Diagonal Axes or Auxiliary Axes:

These additional axes are to be understood as axes which are arranged atan angle between the main axes. These auxiliary axes can be arranged atan angle of 45° in relation to the vertical or horizontal main axis,respectively, and can therefore be the axes conventionally designated asdiagonal axes. However, diagonal axes according to the present inventionare to be understood in general as axes which have an angular deviationsufficient for these applications from the vertical and the horizontalmain axis. Typically, these diagonal main axes preferably enclose,independently of one another, an angle with the horizontal or verticalmain axis, respectively, of 10-80°, preferably in the range of 20-70°,particularly preferably in the range of 30-60°. These diagonal main axesvery particularly preferably enclose an angle with the horizontal orvertical main axis, respectively, in the range of 40-50°, verypreferably an angle in the region of 45° or of precisely 45°. If thereare two such additional axes, they can be perpendicular to one another,i.e., they enclose an angle of 90° with one another, but it is alsopossible that the diagonal main axes enclose an angle in the range of20-160° with one another, for example in the range of 60-120°. Thediagonal main axes preferably enclose an angle of 80-100° with oneanother, in particular an angle in the region of 90° or of precisely90°. Actuation of the electronic device: This actuation, either totransfer into a next individual measurement or to displace the alignmentmark, can be performed either directly on the display screen (forexample, upon use of a touch-sensitive display screen) or else it ispossible to provide an additional input interface. Via this interface,for example, movement information of the user (nodding of the head orother body part movements) can also be registered, either a central unitor a special device for actuation can be provided for the registration,for example, in the case of data spectacles, the movement of thealignment mark can be controlled by movement of the head, by speechinput, or by corresponding manual input on the data spectacles.

Since the vision system is trained to always focus on the point which isto be assessed, for the test subject in the scope of the classicaldetermination of the Vernier acuity via the Amsler grid, it is almostimpossible to fulfill this task without turning the fixation away fromthe requested fixation point. However, the examination thus becomesworthless. The advantage of the test method described here is that thestudied subject has to focus on the point which he has to displace. Thiscorresponds to the normal physiological vision procedure, in that one isable to turn ones visual attention to the point which has to bemanipulated. Since the studied subject aligns the point to bemanipulated in relation to the two outer points which are alsodisplayed, the effectively tested points are these two outer points.This measuring procedure thus enables the measurement of points outsidethe central point of focus, without the studied subject intentionallyhaving to concentrate on points outside the point of focus.

By way of a dynamic adaptation of the test imaging to the effective testconditions (spacing of eye from image or rotation of the head or thescreen), the quality and reliability of the measurements are increased.By way of the additional registration and analysis of the requiredchronological duration of the partial tasks until the user hassubjectively positioned the alignment mark optimally on the connectingstraight line, and also by way of the registration and analysis of thenumber and size of the control movements per partial task, the staticexamination of the Vernier function is expanded by a dynamic component,whereby the sensitivity threshold for the discovery of degenerative oralso pathological changes can be lowered. The method additionallyenables a continuous adaptation of the test and the display to thecapacities and needs of each individual eye of a user.

According to a further preferred embodiment, the present inventionmoreover relates to such a method, which is furthermore characterized inthat in the scope of one test series, at least two or at least threetest procedures are carried out along the vertical main axis and two orat least three test procedures are carried out along the horizontal mainaxis. It is alternatively or additionally possible to carry out at leasttwo or at least three test procedures along each of the two diagonalmain axes.

With reference to these diagonal main axes, it is not to be strictlyunderstood that these inclined main axes have to be at an angle of 45°in relation to the vertical or horizontal main axis, respectively. Whatis essential is that these diagonal main axes have a deviation from thevertical and the horizontal main axis sufficient for these applications.These diagonal main axes typically enclose, preferably independently ofone another, an angle with the horizontal or vertical main axis,respectively, of 10-80°, preferably in the range of 20-70°, particularlypreferably in the range of 30-60°. These diagonal main axes verypreferably enclose an angle with the horizontal or vertical main axis,respectively, in the range of 40-50°, very preferably an angle in theregion of 45° or of precisely 45°.

The two diagonal main axes are preferably perpendicular to one another,i.e., they enclose an angle of 90° with one another, but it is alsopossible that the diagonal main axes enclose an angle in the range of20-160° with one another, preferably in the range of 60-120°. Thediagonal main axes preferably enclose an angle of 80-100° with oneanother, in particular an angle in the region of 90° or of precisely90°.

The arrangement of the test points on various axes enables the testingof various, precisely defined points of the retina. This enablesdegenerative processes which exist from birth or processes which arepathological to be associated with certain areas and points of theretina. In fact, the entire region of the macula can thus be studied indetail. The measuring range extends over at least a circle of a radiusof 10° about the fixation point. Since, according to the proposedmethod, the measured points can be measured very accurately andreproducibly, this association is very accurate, in contrast to othermethods, for example the Amsler grid, which only permits thisassociation imprecisely. It is specifically possible by way ofappropriate skillful control of the measurement or the selected startinglocations along the various main axes, respectively, to effectivelydetermine the weaker regions on the retina for each eye by targeted dataanalysis. Areas can thus be identified on the retina by the differentmeasurements along various axes and with various spacings of thealignment mark from the outer marks, wherein these areas are typicallycircular segments or, as a result of the various spacings of thealignment mark from the outer mark, even circular ring segments. Amapping on a polar grid, as it were, can thus be performed, wherein thevarious grid areas can be assessed individually.

As described above, various parameters can be used as the measure fordetermining the visual acuity of the user. According to a furtherpreferred embodiment, in the case of registration of the parameter ofthe effective spacing of the alignment mark from the connecting straightline after displacement of the alignment mark by the user as the measurefor determining the visual acuity, the mean value and/or the standarddeviation of the absolute value of the effective spacing of the testprocedures along the same main axis is used.

If, additionally or alternatively, a registration is performed of theparameter of the time which the user has required for the displacementof the alignment mark, and this is evaluated as a measure for thedetermination of the visual acuity, the mean value and/or the standarddeviation of the total time between the appearance of the marks and theconfirmation of the end of the individual test procedure can be used.If, as the end of the individual test procedure, for example, the nextmeasuring procedure is proceeded to automatically upon a lack of inputwithin a certain number of seconds, it is also possible to take thatpoint in time as the end at which the last manipulation has taken place.

If, additionally or alternatively, a registration of the number ofdirection changes during the displacement of the alignment mark by theuser is registered as a parameter, the mean value and/or the standarddeviation of the number of direction changes during the individual testprocedures can be used, or the total of the direction changes along acertain main axis. Under this parameter, the amplitude and/or thefrequency of such direction changes can additionally also be registeredand analyzed.

In addition to the parameters specifically mentioned here, still furtherparameters can also be registered and incorporated into the dataanalysis for determining the visual acuity. These include, for example,items of information which are recorded via the camera oriented towardthe user and, for example, items of information about the eye, theactivity of the eye during the measurement, etc. The position of devicerelative to the user, and the movement of the device (via correspondinggyro elements/sensors), and items of information about the brightness ofthe surroundings, the time of day, the time since the last examination,etc. can also be incorporated.

Since the Vernier acuity varies depending on various physiologicalinfluencing factors, for example time of day, learning effect, andalignment of the tested axis, these influencing factors are supplementedby additional analysis of the dynamic test parameters such as requiredduration for the partial tasks and number and size of the requiredcontrol and correction movements. This enables better differentiationbetween changes of the measurement results which are related to visualcapacity and form on the day or are induced by learning effects. Thus,insofar as the method is used to measure retina-related influences onthe visual acuity, non-retina-related influences on the measurementaccuracy can be filtered out or weighted correctly, and the sensitivityof the method for the determination of changes related to visual acuitycan thus be increased. On the other hand, specifically these furtherparameters, if the method intends generally to measure the perceptioncapacity of the user, for example (in the context of an alcohol test,for example), can be taken into account as relevant additionalparameters in the analysis. These further parameters can thus be usedboth for further refinement of the measurement results, and also toprevent the corruption of the measurement results.

According to a further preferred embodiment, the method is characterizedin that test procedures are begun along the same main axis withdifferent offset of the alignment mark in each case along the connectingstraight line, wherein preferably an offset of ⅓, ½, and ⅔ of thedistance between the two outer marks is specified along each main axisat the beginning of the respective test procedure. The number of theindividual test procedures and/or the respective offset can preferablybe adapted individually in this case on the basis of prior examinationresults or preceding morphological examinations. Due to this differentrelative position of the alignment mark in relation to the outer marks,it is possible to measure not only circular sectors on the retina or thefield of vision, respectively, but rather circular ring sectors.

The test method permits the examination of a very large area of theretina. Degenerative, pathological, or other processes are oftenrestricted to narrowly circumscribed regions of the retina, however.Affected regions may be found rapidly in the context of a searchfunction by means of the offset of the points selected at the beginning,and may be more closely delimited in the further course of themeasurement by selection of the location of the measurement points. Thisis because in actual fact it is possible to specifically adapt futuretest series depending on measurement results of previous test series, orto reduce them to the decisive measurements, respectively. By way of thereduction of the number of individual test measurements, the accuracythereof can also be substantially increased, since symptoms of fatigueof the user should have a lower influence.

According to a further preferred embodiment, the outer marks and thealignment mark can be strokes or circles having a length or diameter,respectively, in the range of 1-10 mm, preferably in the range of 2-4mm. In the case of strokes, they can be strokes having a strokethickness in the range of 0.5-5 mm, preferably in the range of 1-2.5 mm.In this case, all strokes are preferably aligned parallel to the mainaxis to be measured during the entire test procedure. The size of theouter marks and the alignment mark can be equal, and they can be adaptedin the size thereof to the visual acuity of the test person.

According to a further preferred embodiment, at least one of thefollowing setting parameters is individually adapted on the basis ofprior test series and/or prior individual test procedures and/orpreceding morphological examinations: the size of the marks; thecontrast on the display screen; the color selection on the displayscreen; optionally additionally provided focusing aids, wherein thisindividualization is preferably performed for each specific eye of theuser.

The user preferably carries out the test series using only one eyeand/or the electronic device ensures that the information displayed onthe display screen can be perceived by only one eye.

The method can thus be individualized both for each eye and each user.Accordingly, depending on measurement results, the shape and size of themarks, the contrast, or possible focusing aids can be individualized foreach eye and displayed for each input during the measuring procedure.

The smaller the measuring marks are selected to be, the more preciselymay the vision quality Vernier acuity be determined. The recognition ofthe test marks is dependent on the vision quality or visual acuity,however. The worse the visual acuity, the larger both the alignment markand the outer marks have to be so that they can be recognized by theexamined person. In the present test, the size, type, and contrast ofthe test mark can therefore optionally be adapted to the visual acuityof the person to be tested. The vision quality Vernier acuity can thusstill be reliably tested in particular in test persons having greatlyreduced visual acuity. This differentiates this test significantly fromother methods for testing the Vernier acuity, for example the Amslergrid, where the test patterns have a constant size. If the visual acuityof the eye to be examined is reduced so much that the test person hasdifficulty in consistently maintaining the fixation on the outer marks,additional focusing aids can be overlaid, for example a ring displaylocated outside the test marks around the entire test field.

A further preferred method is characterized in that the user controlsthe displacement of the alignment mark by a direct or indirectinteraction with the electronic device, wherein this interaction can beperformed by means of a touch-sensitive display screen, body movements,in particular of the hand or the head, or by speech, or a specific inputinterface, for example a manual input device or else via an input devicecoupled on via Bluetooth (for example, if the display screen is producedvia a projection), or a combination thereof, wherein, if the displayscreen is a touch-sensitive display screen, the user either aligns thealignment mark directly by touching and displacing the alignment mark onthe display screen, or does so with the aid of one or more displacementknobs which are depicted on the display screen. The type, size, number,direction, and the time requirement for the interaction of the user withthe input aids for guiding the test mark into the target region can alsobe measured and used for the improvement of the measurement sensitivityand also for the assessment of the form on the day of the user or of thelearning effect.

Since older persons offer suffer from changes of the retina, theinteraction with the measuring device can be made more difficult. Thesedifficulties may be avoided by way of the manifold options forinteraction possible according to the present invention. Theinteractions, using which the test is controlled, correspond to typicaleveryday interaction patterns, in that an interaction is able to beperformed using gestures or head movements such as nodding the head orshaking the head.

As already described, it is possible, by measuring the time untilcorrect positioning of the test mark is achieved, to indirectlydetermine a change of the visual function, in addition to the actualVernier acuity measurement. Even very slight worsening of the visualfunction results in an increased time requirement for the correctpositioning of the test mark. Indications of worsening of the visionfunction in a certain retinal area exist if the time for solving thepartial task on a certain axis or a point becomes longer in comparisonto earlier examinations, or if the difference between the slowly and therapidly solved partial tasks increases in comparison to earlierexaminations. If an increased time requirement for solving the task isestablished on one or more test axes (required time lies outside twostandard deviations, for example, of the time required for these testpoints in earlier examinations), the device will propose a shortenedinterval until the next testing (for example, 3 instead of 7 days). Ifprogressive slowing over multiple measuring days is established,additional measures, for example a request to visit an optician orphysician, or further measures are recommended. If the method determinesthat the time requirement for all tasks increases or decreases, this isan indication of generally better or worse vision function, a varyingform on the day of the user, or a learning effect. This information canbe used to adapt the size of the test marks in the case of anunambiguous trend, or to weight the results differently with respect tothe use in the individual database (baseline for the normal test resultof an axis or an area). This can prevent examination results of testchecks on generally poor days for the user or the effect of the learningcurve from causing the statistical reference value for an expectedperformance of the user on an axis to become incorrectly low. Thesensitivity of the method thus remains consistently high in spite oflearning curve or changed test displays.

The method offers the option, in contrast to the previous measuringmethods with analysis of solely static measured variables of the Verniervision function, by way of the measurement of a dynamic component, ofsubstantially increasing the sensitivity for the discovery of a changeof the Vernier vision function and also of taking into consideration andcompensating for effects such as form on the day, learning curve, orchanged display.

A measurement of the required number of correction movements, which isalso possible as already described above, and also of the size and/oramplitude of the overshooting correction movements until the definitivepositioning of the test mark, can be registered. An increased number ofcorrection movements or an increase in the amplitude of the correctionmovements on one axis or multiple axes in comparison to the valuesdetermined in the preceding examination cycles is an indication of alocal worsening of the Vernier vision function. Indications of worseningof the vision function in a certain retinal area exist if the number ofcorrection movements for solving the partial task on a certain axis or apoint increases in comparison to earlier examinations, or if thedifference between the most and least successfully solved partial tasksincreases in comparison to earlier examinations. Similarly to a measuredworsening of the chronological component of the Vernier vision functiontest, in the event of worsening of the number or the amplitude of thedynamic components of the Vernier vision function test, the method willrecommend a reduced interval until the next test or additional measures.

The advantage of this second component of the dynamic test of theVernier vision function also enables increased sensitivity of theVernier vision function test for the early determination of very slightworsening of the vision function. Moreover, influencing variables, suchas the form on the day or learning effects, of changes related to visualcapacity can be differentiated better, since form on the day andlearning effect influence the number and size of the correctionmovements for all partial tasks, axes, and retinal areas, whilepathological changes predominantly occur in the region of alreadydiseased retinal areas or only individual areas having worse function.

A measurement of the required number of correction movements and thesize (amplitude) of the overshooting correction movements until thedefinitive positioning of the test mark can be performed inconsideration of the static results of the Vernier vision function test(spacing of the mark from the axis). If a strong and general increase ofthe required number and amplitude of the performed correction movements(dynamic component) on all axes is determined without worsening of thestatic test component (increase of the effective spacing of thealignment mark from the connecting straight line), then this is anindication of a change of the form on the day of the test person or aneffect of the learning curve or an effect of the changed test display oris caused by a general slowing of the central nervous system performanceand control of the coordination, for example as a result of sedative,hallucinogenic, or intoxicating substances such as alcohol. In thiscase, the results of this measurement of the Vernier vision function arenot considered or are only considered in a reduced form for thedetermination of the individual reference values of the long-term visionfunction of the test person. This can prevent examination results oftest checks on generally poor days for the user or the effect of thelearning curve from causing the statistical reference value for anexpected performance of the user on an axis to become incorrectly low.The sensitivity of the method thus remains consistently high in spite oflearning curve or changed test displays. In the event of a suddenlyoccurring, substantial deviation from the typical form on the day (morethan 2 standard deviations), the method will recommend to the testperson to take measures or temporarily stop activities (for exampledriving vehicles and using hazardous machines).

The advantage of the combined dynamic and static analysis of the Vernierfunction is that, in addition to a visual component, the responsecapacity of the test person can also be measured. Short-term worseningas a result of the fluctuating form on the day of the test persons(fatigue, time of day, sedative substances) can thus be partially oreven completely differentiated from retina-related worsening. Worseningcaused by the present form on the day can thus be statisticallyunderweighted with respect to the long-term analysis in relation to thesolely retina-related worsening of the vision function. By filtering outthe noise in the Vernier vision function caused by the form on the day,the sensitivity of the test to the solely retina-related changes of theVernier vision function is increased once again.

A further preferred embodiment of the proposed method is characterizedin that a qualitative analysis or a quantitative analysis is output onthe display screen as a function of the determined visual acuity, or anotification that medical aid should be sought.

According to another preferred embodiment, the arrangement of the outermarks and the alignment mark is individually adapted for the variousindividual test procedures on the basis of the statistical analysis ofthe preceding measurements.

In contrast to other measurement methods, the present test permits aquantitative measurement of the Vernier acuity of individual retinalareas. The measurement results of the individual test points are lessinformative taken per se with regard to the dynamics of a pathologicalprocedure and are not interpretable by a user of the test. However, byway of statistical methods in consideration of preceding measurements orother measurement points registered in the same examination, thedynamics of a pathological or degenerative process may be derived. Onlythis information and not the results of individual measurement points issignificant for the user and is directly provided to the user.

The data ascertained in a test series, optionally in combination withitems of information about the user, in personalized or anonymized form,can moreover be transmitted to a central office according to a furtherpreferred embodiment, preferably via an Internet or mobile telephoneconnection, and at this central office, the data can be stored, furtherprocessed, and/or relayed for information and/or further processing tomedical support.

The electronic device can additionally have sensors (including a cameraoriented toward the user, movement sensors/acceleration sensors,orientation sensors, optical or thermal sensors, sound or odor sensors),and can thus determine the behavior of the user, in particular thespacing of the user from the display screen, and/or the eye spacing,and/or whether the test procedure is carried out in a monocular orbinocular manner, and in the first case, which eye is closed in thiscase, and/or the rotation of the display screen about the vision axisand/or the orthogonality of the vision axis to the surface of thedisplay screen. This information may be incorporated into the dataanalysis and/or a notification may be transmitted via the display screenor acoustic signals or speech output to the user to set thecorresponding variable to the correct value. Additionally oralternatively, it is possible to use this information to carry out andrecord the measurement optimally. Thus, the display occurring on thedisplay screen of outer marks and alignment mark can advantageously beadapted, preferably even dynamically adapted within one test procedureor between the test procedures of one series, on the basis of theseitems of information. The camera or other sensors of the electronicdevice can additionally be used for the unambiguous identification of atest person or of the behavior thereof during the measuring procedure oralso before or after, respectively, the measuring procedure (forexample, via facial recognition, fingerprint, or voice recognition). Thelocation or size of the test marks on the display screen can also beadapted dynamically during the test procedure, in particular dependingon the measured effective distance and the rotation of the displayscreen, such that the projection of the measurement points on the retinaremains consistent. Measuring methods for determining the Vernier acuitycan only supply reproducible and quantifiable results if it is ensuredthat identical points on the retina can be measured repetitively. Thepresent invention adapts itself to the user dynamically in this regardby means of sensors.

The electronic device is preferably a portable device, in particular apersonal digital assistant (PDA), smartphone, mobile telephone, tablet,laptop, smart watch, data spectacles, or head-mounted display. In thiscase, the method can be based on a two-dimensional or three-dimensionaldepiction. The testing of the Vernier vision function can be performedin a monocular or binocular manner. Binocular testing results in areduced time requirement for the testing of both eyes. The time savingscan be used if needed for measuring additional areas or for additionalmeasurements on critical areas.

The results of various successively carried out test series, preferablytest series carried out on different days, can be evaluated relative toone another in the development thereof by the electronic device and thedevelopment of the visual acuity can be determined, and preferably uponreaching a threshold value of a variable computed from the test series,a warning can be output to the user and/or can be transmitted via aninterface to a central office for making contact with the user.

The checking of the dynamics of the visual acuity is decisive for thedetection and monitoring of pathological processes. Individualmeasurements taken per se only have limited informative power. Theevaluation within the course increases the informative powersignificantly and also allows other, non-pathological variations of thevision function, which are not of interest, to be filtered out. Byfiltering out the non-pathological variations of the vision function,the accuracy and sensitivity of the method for determining pathologicalchanges can be significantly increased in relation to previous methodsfor determining the Vernier vision function. According to a furtherpreferred embodiment of the method proposed here, the electronic devicecan prompt the user, in the scope of a specified time plan, to carry outa test series in each case at a certain point in time, whereinpreferably, depending on the result of a preceding test series and inparticular depending on changes of the results of the immediatelypreceding test series in relation to the base value determined bymultiple preceding test series, a renewed test series is recommended tothe user in the scope of a fixed time scheme, for example every 3-14days, or preferably every 7 days, or, in the event of establishedworsening of the results, after only an individually shortened timeinterval.

Carrying out vision tests can represent a significant burden for theexamined persons and can therefore have the result that the tests are nolonger carried out or are no longer carried out with sufficient andsuitable attentiveness. Since many retinal diseases are of a chronicnature, testing over long periods of time is necessary. The frequency ofthe test procedures therefore occurs in the present test not accordingto a fixed time scheme, but rather is individually adapted based onprevious measurement results and other factors. In addition,specifically the sequence of the individual measurements can also befocused in a very targeted manner on the problem zones, namely onlythose main axes are measured which are actually relevant for thecorresponding user. The control of the time intervals can also beperformed individually only for the eye having a change of the results(for example, in the event of worsening of the left eye, only therecommended examination interval of the left eye is shortened). Due tothe individual control of the time intervals until the next check, thetime burden on the user can be minimized. Moreover, additionalmeasurements or test axes for improved measurement accuracy or testsensitivity can be added to an eye having worsening, while only a shortbasic check has to be carried out on a stable eye. Moreover, the testperson is prompted to perform the testing in each case.

As already mentioned, according to a further preferred embodiment, themeasurement data of the electronic device can be transmitted to acentral computer and analyzed therein using algorithms. Possiblealgorithms are, for example, the determination of

i) the variance increase of the measurement point spacings relative to acomparative measurement;

ii) the consideration of patient characteristics, such as in particularage, sex, ophthalmological findings such as eyesight, eye diseases, andsystemic diseases;

iii) subjectively experienced degree of difficulty of carrying out thetest, test duration, amount and amplitude of the control and correctionof the test mark and the progression of the test results, and anypossible therapeutic measures.

The results of such analyses can be processed as personalized feedback,preferably individualized each eye, and provided to the user, and theresults can be used to individualize the measuring arrangement, whereinthis individualization can consist in a change of the measurement axes,the measurement points, the measurement interval, and the assessment ofthe measured values. The testing is preferably performed with a coveredeye. The test can also be carried out with both eyes simultaneously,wherein depending on the test results, a prompt can then be made tocarry it out with a covered eye.

Furthermore, the present invention relates to a portable electronicdevice for carrying out a method as was described above, having adisplay screen and a data analysis unit, wherein the display screen ispreferably a touch-sensitive display screen, and wherein furthermore theelectronic device preferably additionally has a camera oriented towardthe user. The display of the test tasks can be performedtwo-dimensionally or three-dimensionally depending on the capability ofthe device used.

Finally, the present invention relates to a data processing program forcarrying out a method as described above on a device as described above,preferably in the form of a mobile application (app).

Further embodiments are specified in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be described hereafter onthe basis of the drawings, which are only used for explanation and arenot to be interpreted as restrictive. In the figures:

FIGS. 1 a) and 1 b) show in FIG. 1 a) a user of the proposed method, whoholds a mobile device at the proposed spacing of approximately 30 cm infront of her eyes, and in FIG. 1 b) a graphic representation of therelative arrangement of outer marks arranged along a horizontal mainaxis and an alignment mark and the corresponding distances and spacingsand also designations for the situation, where the offset isapproximately ⅔;

FIGS. 2 a)-2 d) show the different displays in the proposed method,wherein in FIG. 2 a) the starting situation of an individual testprocedure is shown, in which the outer marks are arranged horizontally,in FIG. 2 b) the location of the alignment mark after manipulation bythe user is shown, in FIG. 2 c) the various main axes are shownsimultaneously, and in FIG. 2 d) the region for the offset isschematically indicated for the situation where the outer marks arearranged horizontally;

FIG. 3 shows possible topographic results of the measurement in a polargrid, wherein the measurement axes are shown in black: these form thecenter lines of retinal sectors, the delimitations of which are shown ingray; the gray areas mark affected retinal sectors; the system can beadapted, made more precise, and optimized in a self-learning manner onthe basis of the analysis of affected sectors on the basis of thetesting in the edge regions.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 a)-b) show a user, who holds a smartphone 2, which has atouch-sensitive display screen 1, in front of her eyes. Software in theform of a mobile application (app), which implements the proposedmethod, is loaded on this smartphone 2. It is to be noted in this casethat the vision axis is aligned substantially perpendicularly inrelation to the surface of the display screen 1, and the longitudinalaxis of the display screen is aligned approximately perpendicularly inrelation to the connecting line of the eyes, in any case the rotation ofthe display screen relative to the face of the user should not bechanged within one test series.

In order that a correct alignment of the smartphone is indicated to theuser, it is possible to also incorporate the camera and optionallyfurther sensors (for example gyroscope and accelerometer) of thesmartphone into the software, and after starting the software, initiallyto determine via the camera or other sensors, respectively, for example,via a corresponding facial recognition of an image of the user recordedby the camera, whether a correct relative position of display screen tothe user is assumed, and if necessary to cause optimum positioning byway of corresponding warning notifications or even by way of concretemodification instructions (for example, “the display screen is located 2cm too close to your eyes, please hold farther away,” or “the monitor istilted in relation to the head direction—please rotate 5° clockwise,” orby overlaying an auxiliary axis), which can be output either visually,in written form, or also acoustically. The incorrect alignment of thedisplay screen in relation to the eyes or deviations of the testdistance can be compensated for continuously and automatically ifnecessary by dynamically changing the location of the points on thedisplay screen during the test sequence, or it is possible to correctthe registered parameters depending on such deviations, so that thedeviations from the correct hold have no influence on the measurementresult. Moreover, via the facial recognition, the person can beidentified the measured side (left or right eye), monocular measurement,and other parameters influencing the quality of the measurement can beremedied and the display or the algorithm of the test sequence can beadapted to the individual visual capacities of the left or right eye,respectively, of a test person or corrected.

Using such sensors (movement sensors/acceleration sensors, orientationsensors, etc.), it is possible to monitor the general behavior of theperson who carries out the test, presuming that the person alwayscarries the measuring device with him. In other words, the measuringdevice can simultaneously also be used as an activity tracker, and thedata determined therefrom can be incorporated into the analysis of thetest procedures described here. Thus, for example, from general activityof the user which remains uniform per se before and after the measuringprocedure, it can be concluded that although the measurement resultswere perhaps somewhat worse, the activity has remained the same, incontrast, and apparently the worse measurement results do not meanlife-changing impairment of the vision behavior. The activity of theuser can also be detected via separate sensors fastened on the body (forexample armband, activity tracker) and transmitted directly orindirectly to the device and/or to a central office, which then takesthis activity into consideration in the analysis of the data transmittedfrom the device to the central office.

The starting location in a first individual test procedure is shown inFIG. 2a . In this case, the main axis 6 is arranged horizontally, i.e.,the two outer marks 3 and 4 are displayed at approximately half theheight on the display screen at the right and left edge, respectively,and the connecting straight line 6 extends horizontally.

It is to be noted in this case that in the effective test, theconnecting straight line 6 shown by dotted lines in each case here inFIGS. 2 a)-2 b) is of course not made visible, but rather isspecifically omitted, so that the user concentrating on the alignmentmark 5 is forced to orient himself to a certain extent by regions whichare not in focus and are defined by the two outer marks 3 and 4 andtherefore to use the regions to be measured accurately.

As the starting situation, the alignment mark 5 arranged more or lessbetween the two outer marks 3 and 4 is displaced substantially downwardin this case and arranged somewhat to the left of the center between thetwo outer marks 3 and 4.

There are now three touch-sensitive regions on the display screen 1 inthe lower region. A first region 13 is indicated on the outside at thefar left, which, upon being touched by the finger, displaces thealignment mark 5 upward, i.e., in this case closer to the connectingstraight line 6 and perpendicularly thereto. A second region 14 isindicated on the outside at the far right, using which the alignmentmark can be displaced in the opposite direction, also perpendicularly tothe connecting straight line. These two regions 13 and 14 are alwaysprovided so that the alignment mark can only be displaced in onedirection or in the opposite direction, respectively, perpendicularly tothe connecting straight line. The arrows shown on the regions 13 and 14,respectively, rotate accordingly, so that the user can recognize whichfunction or which direction, respectively, relative to the connectingstraight line is associated with which knob.

Moreover, a further touch-sensitive region is located in the middle,using which the individual test procedure can be completed and theseries can proceed to the next.

The various touch-sensitive regions 13-15 can also be arranged in otherregions of the overall display screen, of course.

Furthermore, it is to be noted that instead of the regions 13 and 14,respectively, a procedure can also be used in which the positioning ofthe alignment mark 5 can be performed directly by laying a finger on thetouch-sensitive display screen and displacing the finger appropriately.

Proceeding from the starting situation shown in FIG. 2a , the user willnow displace the alignment mark by the actuation of the regions 13 and14, respectively, until he subjectively has the feeling that it islocated on the connecting straight line 6 (which is specifically notshown in the effective experiment, although it is shown in FIG. 2 tofacilitate the description). If the user is of the opinion that thealignment mark 5 is located on the connecting straight line 6, forexample in the position as shown in FIG. 2b , he can progress to thenext individual test procedure by way of the central region 15. When hedoes this, the spacing 7 of the alignment mark 5 from the connectingstraight line 6 is read out and stored by the software. This spacing 7,as described in greater detail hereafter, is used for the analysis. Inaddition, the required time until the test person has subjectivelycorrectly aligned the mark, and the number and amplitude of requireddirection corrections during the displacement of the mark, can also beregistered and subsequently analyzed for the analysis.

Various such individual test procedures are now carried out in a mannerwhich appears random to the user, wherein in each case at least threetest procedures are carried out along one main axis (cf. description ofFIG. 2c ).

The various main axes measured in this case are shown in FIG. 2c . Onthe one hand, the horizontal main axis 9, as is also illustrated in theindividual test procedure according to FIGS. 2a and b , then thevertical main axis 8, and also a first diagonal main axis 10 and asecond diagonal main axis 11.

If all main axes are measured and three measurements are performed oneach main axis, this results in 12 measurements, which can sometimesalso be perceived as burdensome. To keep the number of actually usefulmeasurements as low as possible or to represent slight changes betterand earlier by way of focal point measurements at the edge of thediseased retinal areas, it is possible by transmitting the measured dataof a test series to a central computer in each case to compare theindividual test procedures to earlier test results and adapt them forlater measurement series to those areas which were actually previouslyfound to be problematic. For example, if a user has a weakness which ismanifested by the measurements on the second diagonal main axis, but noproblems on the first diagonal main axis, it is thus possible for thefirst diagonal main axis not to be measured during each test series orfor only individual measurements and no longer multiple measurementsstill to be performed per axis. The analysis of the results andadaptation of the test sequence are preferably performed individuallyfor each tested eye.

As described above, the alignment marks are presented during theindividual test procedures in different positions relative to the twoouter marks in the starting situation. The offset 12 which is reasonablypossible in this case is illustrated in FIG. 2d . This offset typicallymoves between either the center or between ⅓ and ⅔ of the distancebetween the two outer marks 3, 4. To make a measurement result moreprecise, to prepare a retina mapping (FIG. 3), to determine the field ofvision or as a reaction to pronounced vision restrictions of an eye, thetest procedure can be displayed in an individualized form for each eyewith respect to the shape and size of the outer marks, the spacingsthereof, the contrast, possible additional focusing aids, or othermeasures, such as color change.

For the analysis of the actual test procedures within the test series,the spacings 7 which the alignment mark 5 has in each case at the pointin time when the user changes to the next individual test procedure (cf.FIG. 2b ) are now collected and statistically analyzed. In this case,for example, a procedure can be used such that the mean value of theabsolute value of the measurements along a certain axis is used, andalso the scattering thereof. Subsequently, mean value and scattering inrelation to each of the 4 axes can be output as a measurement result.Further parameters gathered during the measurement, for example, theduration of the entire examination or the duration until the positioningof individual points, and also the number and size or amplitude of thecorrection movements and/or the changes of these parameters uponrepeated measurements, can additionally be used to improve themeasurement or to reduce the detection threshold for pathologicalchanges. Furthermore, it is possible that the damaged areas areidentified along each main axis and fine mapping of the correspondingretinal section can be completed there. The spacings of the outer marksfor individual axes can be adapted in conjunction with the retinalmapping.

The measurement result can either be generated autonomously on thesmartphone itself, or else a procedure can also be used in which the rawinformation (individual measurement points) is transferred to a centralserver, the analysis takes place therein, in particular also dependingon already completed test series, and feedback occurs after centralanalysis.

In the case of communication with a central computer, it is alsopossible to have corresponding feedback be sent not only to the user,but rather also, for example, to an optician or medical personnel.

The feedback can, on the one hand, consist of statistical analysis withnumbers or, on the other hand, be performed in a more detailed form, forexample with the prompt to visit an optician or medical personnel, totake further measures, or to stop activities, for example drivingvehicles or operating hazardous machines.

It is possible, for example, to prompt the user initially or in eachcase at defined intervals to carry out an initialization measurementseries, which more or less determines a baseline of the individualcapacities. A variation range which is characteristic for thecorresponding user is determined from these initialization measurements,preferably individually for each measured axis. This means that uponmeasurement of the horizontal and the vertical axis and also the twodiagonal axes, four variation ranges are determined in theseinitialization measurements, one for each axis. This means that alongeach axis, the obtained measured values in this initializationmeasurement are subjected to a statistical analysis individually foreach axis, and an individual variation range is then established for therespective axis. This is preferably performed such that twice thestandard deviation of the spacing of the alignment mark from theconnecting straight line is used as the variation range.

Direct and helpful feedback, which is useful for the user, via thedisplay screen can then be embodied independently of the furtherstatistical analysis of the measurements in the background so that whenall 4 axes have been measured in the respective performance of the testseries, for each individual test procedure in which the user aligns thealignment mark within the defined variation range (specifically, forexample, within the range+/−standard deviation as determined from theinitialization measurement series, wherein this standard deviation canbe adapted successively proceeding from values determined in aninitialization measurement series in the course of regular continuationthe test series over a relatively long period of time), a point isawarded. If 3 measurements are carried out per axis along the 4 axes, amaximum of 12 points per test series thus results. After completion ofthe test series, the number of achieved points can be output via thedisplay screen, and backed with additional optical feedback. Thus, forexample, the deviation from the maximum number of points can beindicated as a measure of the quality of the test series, and uponreaching 11 or 12 points, a value of 0 or 1, respectively, can beoutput, backed with green, in the sense of everything in order, nofurther action required, upon reaching 9 or 10 points, a value of 2 or3, respectively, can be output, backed with orange, in the sense ofcaution, the development is not advantageous, and upon reaching lessthan 9 points, the corresponding difference value can be output, backedwith red in each case in the sense of caution, action required, pleasecontact the physician. The corresponding scale and/or at which number ofpoints which warning, is output visually or supplemented by additionalmessages, also optionally via the audio output, can also be setindividually depending on the medical situation, age, and preference ofthe user.

The test is preferably carried out with only one eye. With devices inthe case of which both eyes can see the same image displaysimultaneously (for example smartphone, tablet computer, and the like),the other eye is preferably covered or closed. If an eyepatch is usedfor covering, patterns, characters, or machine-readable codes (forexample QR code) can be applied thereon, which the camera can registerand thus can obtain data (for example on the test person). A binocularperformance of the test is also possible with the above-mentioneddevices, wherein the worsening of the vision function can initially notreliably be associated with a certain eye. If a change of the visionfunction is noticed during the binocular examination, the examinedperson can be requested to carry out monocular tests. The eye which mustbe tested is determined on the basis of the results of the precedingexaminations and/or the progression thereof. In the case of screenshaving the option of a three-dimensional (spatial) display, by using anadditional offset of the test mark in the third dimension, the testaccuracy of a binocular test can be improved. When carrying out the testwith data spectacles or devices which display a three-dimensional orvirtual reality or can present a different image to each eye, coveringthe contralateral eye can also be omitted in the case of monoculartesting.

LIST OF REFERENCE NUMERALS 1 display screen 2 electronic device, mobiletelephone, smartphone, smart watch, data spectacles 3 outer mark 4 outermark 5 alignment mark 6 connecting straight line 7 effective spacingafter manipulation by the user 8 vertical main axis 9 horizontal mainaxis 10  first diagonal main axis 11  second diagonal main axis 12 offset 13  touch-sensitive region for displacing the alignment mark in afirst direction perpendicular to the connecting straight line 14 touch-sensitive region for displacing the alignment mark in a seconddirection perpendicular to the connecting straight line 15 touch-sensitive region for input of the end of the individual testprocedure 16  permitted displacement direction for the alignment mark aoffset b complementary offset in relation to the total distance d cspacing of the alignment mark d total distance between the outer marks

The invention claimed is:
 1. A method for determining the visual acuityof a user, in which, in the scope of a plurality of individual testprocedures carried out in succession and conducted in the manner of atest series, in the scope of each individual test procedure, twospaced-apart outer marks, which are fixed within an individual testprocedure, and an alignment mark located therebetween but not on aconnecting straight line of the outer marks, are displayed to the useron a display screen of an electronic device, the user is prompted, byactuating the electronic device, to displace the alignment mark on thedisplay screen exclusively perpendicularly to the connecting straightline of the outer marks until in the perception of the user thealignment mark lies on the connecting straight line, and subsequently,after completed displacement of the alignment mark by the user, theelectronic device registers at least one of the following parameters:the effective spacing of the alignment mark from the connecting straightline after displacement of the alignment mark by the user; the timewhich the user has required for the displacement of the alignment mark;and the number of direction changes during the displacement of thealignment mark by the user, wherein at least two or at least threeindividual test procedures are carried out, in which the outer marks arearranged along a same main axis or previously determined auxiliary axes,and wherein the tests are measured with the outer marks arranged alongat least two different main axes in the scope of one test series,wherein the at least one registered parameter or, upon measurement ofmultiple parameters, a combination of the registered parameters is usedas a measure for determining the visual acuity from the individual testprocedures of the test series, and wherein in the scope of one testseries, at least two test procedures are carried out along a verticalmain axis and two test procedures are carried out along a horizontalmain axis, and at least two test procedures are carried out in each casealong at least one of two diagonal main axes.
 2. The method as claimedin claim 1, wherein: in the case of registration of the parameter of theeffective spacing of the alignment mark from the connecting straightline after displacement of the alignment mark by the user as the measurefor determining the visual acuity, at least one of the mean value andthe standard deviation of the absolute value of the effective spacing ofthe test procedures along the same main axis is used; or in the case ofregistration of the parameter of the time which the user has requiredfor the displacement of the alignment mark as the measure for thedetermination of the visual acuity, the mean value and/or the standarddeviation of the total time between the appearance of the marks and theconfirmation of the end of the individual test procedure by the user isused; or upon registration of the parameter of the number of directionchanges during the displacement of the alignment mark by the user, atleast one of the mean value and the standard deviation of the number ofdirection changes during the individual test procedures is used or thetotal of the direction changes along a certain main axis, or at leastone of the size and amplitude of the overshooting correction movementsuntil the definitive positioning of the test mark.
 3. The method asclaimed in claim 1, wherein test procedures are begun along the samemain axis with different offset of the alignment mark in each case alongthe connecting straight line.
 4. The method as claimed in claim 3,wherein an image of the user or an eyepatch used by the user isadditionally registered as a parameter, and items of information aboutthe eye used or the user carrying out the experiment are used for theanalysis.
 5. The method as claimed in claim 1, wherein the outer marksand the alignment mark are strokes or circles having a length ordiameter, respectively, in the range of 1-10 mm, and in the case ofstrokes having a stroke thickness in the range of 0.5-5 mm.
 6. Themethod as claimed in claim 1, wherein the user carries out the testseries using only one eye, or wherein the electronic device ensures thatthe information displayed on the display screen can be perceived by onlyone eye.
 7. The method as claimed in claim 1, wherein the user controlsthe displacement of the alignment mark by a direct or indirectinteraction with the electronic device, wherein the interaction can beperformed by means of a touch-sensitive display screen, body movements,or by speech, or a combination thereof, and wherein, if the displayscreen is a touch-sensitive display screen, the user either aligns thealignment mark directly by touching and displacing the alignment mark onthe display screen, or does so with the aid of one or more displacementknobs which are depicted on the display screen.
 8. The method as claimedin claim 1, wherein a qualitative analysis or a quantitative analysis isoutput on the display screen as a function of the determined visualacuity, or a notification that medical aid should be sought, or whereinthe arrangement of the outer marks and the alignment mark isindividually adapted for the various individual test procedures on thebasis of the statistical analysis of the preceding measurements.
 9. Themethod as claimed in claim 1, wherein the data ascertained in a testseries, without or in combination with items of information about theuser, in personalized or anonymized form, are transmitted to a centraloffice, and at the central office the data are at least one of stored,further processed, and relayed for at least one of information andfurther processing to medical support.
 10. The method as claimed inclaim 1, wherein the electronic device additionally has sensors, andthus determines the behavior of the user.
 11. The method as claimed inclaim 1, wherein the electronic device is a portable device, including aPDA, smartphone, mobile telephone, tablet, laptop, smart watch, dataspectacles, or head-mounted display.
 12. The method as claimed in claim1, wherein the results of various successively carried out test series,are evaluated relative to one another in the development thereof by atleast one of the electronic device and a central computer and thedevelopment of the visual acuity is determined, and upon reaching athreshold value of a variable computed from the test series, a warningis output to the user or transmitted via an interface to a centraloffice for making contact with the user, and/or wherein the electronicdevice prompts the user, in the scope of a predefined time plan, tocarry out a test series in each case at a certain point in time, and/orwherein in the determination of the visual acuity, variations which arenot caused solely by the mere visual acuity, are substantially orcompletely eliminated; and/or wherein variations not caused solely bythe mere visual acuity, including variations depending on the form onthe day, are taken into consideration in the analysis.
 13. The method asclaimed in claim 1, wherein the measurement data of the electronicdevice are transmitted to a central computer and analyzed therein usingalgorithms, wherein the results of such analyses can be processed aspersonalized feedback, and provided to the user, and the results can beused to individualize the measuring arrangement, and wherein theindividualization can consist in a change of the measurement axes, themeasurement points, the measurement interval, and the assessment of themeasured values.
 14. A portable electronic device for carrying out amethod as claimed in claim 1, having a display screen and a dataanalysis unit.
 15. A data processing program for carrying out a methodas claimed in claim 1 on a portable electronic device having a displayscreen and a data analysis unit.
 16. The method as claimed in claim 1,wherein in the scope of one test series, at least two or at least threetest procedures are carried out along the vertical main axis and two orat least three test procedures are carried out along the horizontal mainaxis, and/or at least two or at least three test procedures are carriedout in each case along at least one of the two diagonal main axes,wherein in the case of weaknesses of the user registered along certainmain axes, these main axes are measured or subsequently only measuredsubstantially exclusively, or wherein conclusions are drawn about thecapacities of certain areas in the retinal region from the visualcapacity determined along certain main axes, and wherein these areas aredefined in the polar grid of a polar coordinate system as circularsectors or circular ring sectors.
 17. The method as claimed in claim 1,wherein test procedures are begun along the same main axis withdifferent offset of the alignment mark in each case along the connectingstraight line, wherein an offset of ⅓, ½, and ⅔ of the distance betweenthe two outer marks is specified along each main axis at the beginningof the respective test procedure, and wherein the number of theindividual test procedures or the respective offset are adaptedindividually on the basis of previous test series or precedingmorphological examinations.
 18. The method as claimed in claim 1,wherein the outer marks and the alignment mark are strokes or circleshaving a length or diameter, in the range of 2-4 mm, and in the case ofstrokes having a stroke thickness in the range of 1-2.5 mm, wherein allstrokes are aligned parallel to the main axis to be measured during theentire test procedure, wherein the size of the outer marks and thealignment mark are equal, and the marks are adapted in the size thereofto the visual acuity of the test person, or wherein at least one of thefollowing setting parameters is individually adapted on the basis ofprior test series or prior individual test procedures or precedingmorphological examinations: the size of the marks; the contrast on thedisplay screen, the color selection on the display screen; optionallyadditionally provided focusing aids, wherein the individualization canbe performed for each specific eye of the user.
 19. The method asclaimed in claim 1, wherein the user controls the displacement of thealignment mark by a direct or indirect interaction with the electronicdevice, wherein the interaction can be performed by means of atouch-sensitive display screen, body movements, of the hand or the head,or by speech, or a combination thereof, and wherein, if the displayscreen is a touch-sensitive display screen, the user either aligns thealignment mark directly by touching and displacing the alignment mark onthe display screen, or does so with the aid of one or more displacementknobs which are depicted on the display screen.
 20. The method asclaimed in claim 1, wherein the data ascertained in a test series,without or in combination with items of information about the user, inpersonalized or anonymized form, are transmitted to a central office,via an Internet or mobile telephone connection, and at the centraloffice the data are stored, further processed, or relayed forinformation or further processing to medical support.
 21. The method asclaimed in claim 1, wherein the electronic device additionally hassensors, in the form of a camera oriented toward the user, and thusdetermines the behavior of the user, including at least one of thespacing of the user from the display screen, and the eye spacing, andwhether the test procedure is carried out in a monocular or binocularmanner, and in the first case, which eye is closed in this case, or therotation of the display screen about the vision axis or theorthogonality of the vision axis to the surface of the display screenand enables this to be incorporated into the data analysis or transmitsa notification via the display screen to the user to set thecorresponding variable to the correct value and/or to dynamically adapt,the display occurring on the display screen of outer marks and alignmentmark on the basis of these items of information.
 22. The method asclaimed in claim 1, wherein the electronic device is a portable device,in the form of a PDA, smartphone, mobile telephone, tablet, laptop,smart watch, data spectacles, or head-mounted display.
 23. The method asclaimed in claim 1, wherein the results of various successively carriedout test series carried out on different days, are evaluated relative toone another in the development thereof by the electronic device or acentral computer and the development of the visual acuity is determined,and upon reaching a threshold value of a variable computed from the testseries, a warning is output to the user and/or transmitted via aninterface to a central office for making contact with the user, and/orwherein the electronic device prompts the user, in the scope of apredefined time plan, to carry out a test series in each case at acertain point in time, wherein, depending on the result of a precedingtest series and depending on changes of the results of the immediatelypreceding test series in relation to the base value determined bymultiple preceding test series, a renewed test series is recommended tothe user in the scope of a fixed time scheme, which can be every 3-14days, or every 7 days, or, in the event of an established worsening ofthe results, after only an individually shortened time interval, and/orwherein in the determination of the visual acuity, variations which arenot caused solely by the mere visual acuity, including variationsdepending on the form on the day, are substantially or completelyeliminated, wherein this is performed by corresponding consideration ofthe time which the user has required for the displacement of thealignment mark or the number of direction changes during thedisplacement of the alignment mark by the user; and/or wherein upon theuse of the determined visual acuity for inference about the state of theuser, in the context of a test for response capacity, includingdetermination of the influence of drugs or medications, variations notcaused solely by the mere visual acuity, including variations dependingon the form on the day, are taken into consideration in the analysis,and wherein this can be performed by corresponding consideration of thetime which the user has required for the displacement of the alignmentmark or the number of direction changes during the displacement of thealignment mark by the user, or by further parameters determined bysensors of the device.
 24. The method as claimed in claim 1, wherein themeasurement data of the electronic device are transmitted to a centralcomputer and analyzed therein using algorithms: i) the variance increaseof the measurement point spacings relative to a comparative measurement;ii) the consideration of patient characteristics, including age, sex,ophthalmological findings including eyesight, eye diseases, and systemicdiseases; and iii) subjectively experienced degree of difficulty ofcarrying out the test, test duration, amount and amplitude of thecontrol and correction of the test mark and the progression of the testresults, mobility behavior of the user, and any possible therapeuticmeasures, wherein the results of such analyses can be processed aspersonalized feedback, with our without individualization for each eye,and provided to the user, and the results can be used to individualizethe measuring arrangement, and wherein this individualization canconsist in a change of the measurement axes, the measurement points, themeasurement interval, and the assessment of the measured values.
 25. Aportable electronic device for carrying out a method as claimed in claim1, having a display screen and a data analysis unit, wherein the displayscreen is a touch-sensitive display screen, and wherein the electronicdevice additionally has a camera oriented toward the user.
 26. A dataprocessing program product comprising a non-transient storage mediumcarrying a program for carrying out a method as claimed in claim 1 on aportable electronic device having a display screen and a data analysisunit, in the form of a mobile application (app).
 27. A method fordetermining the visual acuity of a user, in which, in the scope of aplurality of individual test procedures carried out in succession andconducted in the manner of a test series, in the scope of eachindividual test procedure, two spaced-apart outer marks, which are fixedwithin an individual test procedure, and an alignment mark locatedtherebetween but not on a connecting straight line of the outer marks,are displayed to the user on a display screen of an electronic device,and the user is prompted, by actuating the electronic device, todisplace the alignment mark on the display screen exclusivelyperpendicularly to the connecting straight line of the outer marks untilin the perception of the user the alignment mark lies on the connectingstraight line, and subsequently, after completed displacement of thealignment mark by the user, the electronic device registers at least oneof the following parameters: the effective spacing of the alignment markfrom the connecting straight line after displacement of the alignmentmark by the user; the time which the user has required for thedisplacement of the alignment mark; and the number of direction changesduring the displacement of the alignment mark by the user, wherein atleast two or at least three individual test procedures are carried out,in which the outer marks are arranged along a same main axis orpreviously determined auxiliary axes, and wherein the tests are measuredwith the outer marks arranged along at least two different main axes inthe scope of one test series, wherein the at least one registeredparameter or, upon measurement of multiple parameters, a combination ofthe registered parameters is used as a measure for determining thevisual acuity from the individual test procedures of the test series,and wherein test procedures are begun along a same main axis withdifferent offset of the alignment mark in each case along the connectingstraight line.
 28. The method as claimed in claim 27, wherein in thescope of one test series, at least three test procedures are carried outalong the vertical main axis and at least three test procedures arecarried out along the horizontal main axis, and/or at least two or atleast three test procedures are carried out in each case along at leastone of the two diagonal main axes.
 29. The method as claimed in claim27, wherein test procedures are begun in each dimension in eachexperiment with the same distance between the outer marks.
 30. A methodfor determining the visual acuity of a user, in which, in the scope of aplurality of individual test procedures carried out in succession andconducted in the manner of a test series, in the scope of eachindividual test procedure, two spaced-apart outer marks, which are fixedwithin an individual test procedure, and an alignment mark locatedtherebetween but not on a connecting straight line of the outer marks,are displayed to the user on a display screen of an electronic device,and the user is prompted, by actuating the electronic device, todisplace the alignment mark on the display screen perpendicularly to theconnecting straight line of the outer marks until in the perception ofthe user the alignment mark lies on the connecting straight line, andsubsequently, after completed displacement of the alignment mark by theuser, the electronic device registers at least one of the followingparameters: the effective spacing of the alignment mark from theconnecting straight line after displacement of the alignment mark by theuser; the time which the user has required for the displacement of thealignment mark; and the number of direction changes during thedisplacement of the alignment mark by the user, wherein at least two orat least three individual test procedures are carried out, in which theouter marks are arranged along a same main axis or previously determinedauxiliary axes, and wherein the tests are measured with the outer marksarranged along at least two different main axes in the scope of one testseries, wherein the at least one registered parameter or, uponmeasurement of multiple parameters, a combination of the registeredparameters is used as a measure for determining the visual acuity fromthe individual test procedures of the test series, and wherein testprocedures are begun in each dimension in each experiment with the samedistance between the outer marks and along a same main axis withdifferent offset of the alignment mark in each case along the connectingstraight line.
 31. The method as claimed in claim 30, wherein the useris prompted, by actuating the electronic device, to displace thealignment mark on the display screen exclusively perpendicularly to theconnecting straight line of the outer marks until in the perception ofthe user the alignment mark lies on the connecting straight line.